[blablablame]

Yes, but it takes something like 30 people working on it (honestly no idea how many are required)? so 7 months * 30 and we are getting close to 18 man years.

[maxerickson]

For a modest house you wouldn't have much more than 5 people on site at any given time.

[StavrosK]

You aren't counting the work that went into creating bricks, tiles and two-by-fours. You have to start from trees, clay and marble.

[bobwaycott]

That doesn't negate the parent's point, of course.